In order to isolate the occupants or other contents of a vehicle from road shocks and vibrations, that part of the vehicle weight which consists of the vehicle body, frame and engine plus transmission is supported on the axles and wheels or springs having a low rate or force/deflection characteristic. Such comparatively soft springs are particularly necessary on vehicles with high pressure radial tires whose own isolation function is greatly reduced by their high effective spring rate.
However, the use of soft vehicle support springs gives rise to another problem, namely excessive body rollout due to the centrifugal force acting on the spring mass in sharp turns. In such turns, the comparatively high centripetal acceleration V.sup.2 /R of the sprung mass (vehicle velocity V, path radius R) requires large rollout sprung deflections to make the sprung mass follow the path of unsprung mass during the turn. Such large rollouts are undesirable because of passenger discomfort and because they can lead to loss of vehicle control.
It is an object of this invention to eliminate rollout without the use of an anti-roll torsion bar and without hydraulic cylinder biasing. A further object of this invention is to provide independent springing at all four wheels for superior road disturbance isolation from the sprung mass.